Bias setting in a scent delivery system

ABSTRACT

A scent delivery system includes scent delivery units that are configured to deliver scent at a variable scent level by being turned on and off successively according to a variable duty cycle. The scent delivery units are associated with corresponding base scent settings. The scent delivery system also includes a central controller configured to control the scent delivery units by generating command data based on a scenting schedule that indicates a desired activation time for more than one implicated scent delivery unit. The scenting schedule is configured to further indicate a scent level bias to be applied to the base scent settings that are associated with different of the implicated scent delivery units. The central controller is configured to generate the command data, based upon a variation in the scent level bias, that takes into account a corresponding variation to duty cycles that are associated with different of the implicated scent delivery units and to communicate the command data to the different implicated scent delivery units.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Ser. No. 13/939,162, filed onJul. 10, 2013, which is related to U.S. patent application Ser. No.13/939,159, filed Jul. 10, 2013, titled “RELATEDNESS IN A SCENT DELIVERYSYSTEM” and U.S. patent application Ser. No. 13/939,165, filed Jul. 10,2013, titled “SCENT DELIVERY SYSTEM SCHEDULING,” the disclosure of eachof which is hereby incorporated by reference in its entirety for allpurposes.

TECHNICAL FIELD

This document describes a scent delivery system that enables scentlevels of one or more scent delivery machines to be varied.

BACKGROUND

Products can be developed to deliver scents or aromas in commercial oroffice environments, such as in a hotel or a retail setting. The scentscan improve a customer's perception of the environment and can helpinfluence customer behavior. Scents and systems can be customized toreflect and complement various activities, events, brands, moods, orenvironments.

SUMMARY

In one general aspect, a scent delivery system includes scent deliveryunits that are configured to deliver scent at a variable scent level bybeing turned on and off successively according to a variable duty cycle.The scent delivery units are associated with corresponding base scentsettings. The scent delivery system also includes a central controllerconfigured to control the scent delivery units by generating commanddata based on a scenting schedule that indicates a desired activationtime for more than one implicated scent delivery unit. The scentingschedule is configured to further indicate a scent level bias to beapplied to the base scent settings that are associated with different ofthe implicated scent delivery units. The central controller isconfigured to generate the command data, based upon a variation in thescent level bias, that takes into account a corresponding variation toduty cycles that are associated with different of the implicated scentdelivery units and to communicate the command data to the differentimplicated scent delivery units.

Implementations may include one or more of the following features. Forexample the central controller may be configured to vary the duty cyclesthat are associated with different of the implicated scent deliveryunits based on the scent level bias by varying the duty cycles accordingto an arithmetic function. The central controller may be configured tovary the duty cycles that are associated with different of theimplicated scent delivery units based on the scent level bias by varyingthe duty cycles according to an geometric function. The centralcontroller may be configured to vary the duty cycles that are associatedwith different of the implicated scent delivery units based on the scentlevel bias and scent types that are associated with different of theimplicated scent delivery units. The central controller may beconfigured to vary cycle times that are associated with different of theimplicated scent delivery units based on the scent level bias. The scentdelivery units may be configured to turn on and off successivelyaccording to a variable duty cycle that ranges between 5% and 95%. Thecentral controller may be configured to vary the base scent settingsthat are associated with different of the implicated scent deliveryunits based on scent types that are associated with different of theimplicated scent delivery units. The scent delivery units may beconfigured to deliver scent at a variable scent level by varying one ormore of fan speed, nozzle pressure, and compressor power of each scentdelivery unit. Based upon a variation in the scent level bias, thecentral controller may send command data that takes into account acorresponding variation to a corresponding one or more of fan speed,nozzle pressure, and compressor power of the implicated scent deliveryunits. The central controller may generate and send a signal to multiplescent delivery units, where the signal reflects a duty cycle thatreflects power characteristics to be applied in successively turning thescent delivery units on and off. The central controller may generate andsend a signal to multiple scent delivery units, where the signal is apulse that corresponds to the multiple scent delivery units being turnedon or off. The central controller may generate and send a differentsignal to each of at least two scent delivery units, where eachdifferent signal reflects a duty cycle that reflects powercharacteristics to be applied in successively turning a correspondingscent delivery unit on and off. The central controller may generate andsend signals to each of at least two scent delivery units, where thesignals sent to a first of the at least two scent delivery units vary intime relative to the signals sent to a second of the at least two scentdelivery units. The signals may include pulses that correspond to thecorresponding scent delivery unit being turned on or off.

Other embodiments of this aspect include corresponding methods andcomputer-readable storage mediums.

The details of one or more implementations described in thisspecification are set forth in the accompanying drawings and thedescription below. Other potential features and aspects of the subjectmatter will become apparent from the description, the drawings, and theclaims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of a scent delivery system.

FIG. 2 is a flow chart of a process for activating a scent delivery unitwithin the scent delivery system.

FIG. 3 shows sample graphical windows illustrating inputting informationregarding a scent delivery unit.

FIG. 4 shows sample graphical windows illustrating inputting informationregarding a scheduled event for one scent delivery unit.

FIG. 5 is a graphical representation of scheduled events from FIG. 4.

FIG. 6 illustrates duty cycles before and after a bias.

FIG. 7 shows a sample graphical window illustrating multiple scentdelivery units in a group.

FIG. 8 shows sample graphical windows illustrating inputting informationregarding a scheduled event for a group of scent delivery units.

FIG. 9 is a graphical representation of scheduled events from FIG. 8.

FIG. 10 is a block diagram of an implementation of a central controller.

FIG. 11 is a flow chart of a process for activating a scent deliveryunit in relation to the central controller of FIG. 10.

FIG. 12 is an implementation of a scent delivery unit.

FIG. 13 is another implementation of a scent delivery unit.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

A scent delivery system can include one or more scent delivery unitsthat are configured to release a fragrance or a scent in a controlledmanner. By distributing the one or more scent delivery units, ormachines, throughout a scenting environment, a desired scent profile canbe generated in the environment. In some scenting environments, such asa hotel, the desired scent profile can vary according to location withinthe space, time of day, day of the week, etc. By incorporating a networkcontrolled scent delivery system, a user can control the one or morescent delivery units, either individually or as a group, through acentral controller. As further detailed below, one or more scentintensities associated with a single unit or a group of units may bescheduled and adjusted through the central controller. In some cases, asingle adjustment may be made to effect a change in a bias settingapplicable to scent intensities of multiple scent delivery units.

Referring to FIG. 1, a scent delivery system 100 includes a centralcontroller 102 that is connected to one or more scent delivery units 104across a network 106. The central controller 102 is configured tocontrol the activation and deactivation of each scent delivery unit 104based on a user-defined schedule. The central controller 102 can alsoinclude, or have access to, a database that contains information abouteach scent delivery unit 104. Such information may include, for example,the location and the scent type of each scent delivery unit 104.

The network 106 is configured to enable direct or indirectcommunications between the central controller 102, the scent deliveryunits 104, and a user device 108. Examples of the network 106 includethe Internet, Wide Area Networks (WANs), Local Area Networks (LANs),analog or digital wired and wireless telephone networks (e.g., PublicSwitched Telephone Network (PSTN), Integrated Services Digital Network(ISDN), and Digital Subscriber Line (xDSL)), radio, television, cable,satellite, and/or any other delivery or tunneling mechanism for carryingdata. In some implementations, the network 106 includes wired orwireless network systems including, but not limited to, wired Ethernet,Wi-Fi, and ZigBee. In some implementations, the network 106 may be madeup of direct connections, either wired or wireless, between the scentdelivery units 104 and the central controller 102.

Each scent delivery unit 104 is configured to deliver one or more scentsand includes a mechanism for releasing the one or more scents into theair. Each scent delivery unit 104 can also include a network module forcommunicating with the central controller 102 through the network 106.In some implementations, one or more scent delivery units 104 can beassociated with a separate network module to establish communicationwith the central controller 102. This way, for example, pre-existingscenting machines without networking capabilities may be deployed in thesystem 100 and controlled via the central controller 102. In someimplementations, the scent delivery units 104 can directly communicatewith each other, for example via a mesh network, so that establishingcommunication between each scent delivery unit 104 and the centralcontroller 102 may not be required.

In one implementation, each scent delivery unit 104 includes a scentreservoir and an atomizing device in fluid communication with the scentreservoir. In one example, the scent reservoir is a cartridge bottlecontaining scented liquid, for example a fragrant oil mixture, thatemits a desired scent for the particular scent delivery unit 104. Theatomizing device can be, for example, a venturi-type atomizer that usesa high velocity airstream, generated by an integrated or a separatecompressor, to draw in and atomize the liquid in the cartridge bottleinto small particles (e.g., under 10 microns in diameter) that can bedispersed into the air to generate the desired scent. Movement ofatomized scent particles within a scenting environment can further beaided by airflow generated by a heating, ventilation, and airconditioning (HVAC) system.

A level of scent (also referred to as an intensity of scent) associatedwith each scent delivery unit 104 may need to be adjusted depending onthe particular application and may be done so in one of several ways.For example, the pressure and/or velocity of the atomizing air streamcan be increased to atomize and disperse more scent particles into theair, thus resulting in an increased scent level. Alternatively, oradditionally, precise control of scent levels may be achieved byoperating the scent delivery unit 104 under a duty cycle. That is, byturning the scent delivery unit 104 on and off successively inaccordance with power characteristics indicated by the duty cycle duringthe time of activation, the total amount of scent particles releasedinto the environment, and therefore the scent level, can be preciselycontrolled. A cycle time of each scenting unit 104, i.e. the period oftime during which one on-off cycle occurs, may also be varied to achievea desired result. For example, given the same duty cycle, a scentingunit 104 operating under a long cycle time will result in a longer offtime between each cycle, thereby increasing the period during which acustomer may regain his/her olfactory sensitivity and helping to reduceodor fatigue that may result from prolonged exposure to scent.

As used herein, “scent level” may refer to a total number of scentparticles released in an environment during a given amount of time.Under this definition, a scenting scheme, for example, that constantlyreleases N number of particles into the environment per second duringactivation time T may be said to produce the same scent level as analternative scenting scheme in which 2×N number of particles per secondare released during time T under a duty cycle of 50%—since in bothcases, the same total number of scent particles would be released duringtime T. Under the latter scenting scheme, if the particles are releasedat a constant rate during the ON portion of the duty cycle, thenincreasing or decreasing the duty cycle would result in a correspondingchange to the scent level.

Notably, a strength of the scent as perceived by the user may be relatedbut not directly linked to the scent level. For example, even if thesame machine operates under different scent levels during multipleperiods of activation, the strength of the scent as perceived by theuser across such periods may not change. This is because a multitude ofother factors, such as temperature, humidity, type of scent, number ofpeople in the room, HVAC settings, etc., not to mention an individual'sscent perception abilities, may affect how strong a particular scent isperceived by the user within the particular scenting environment.

In some implementations, each scent delivery unit 104 may be associatedwith a base scent setting. The base scent setting may refer tomachine-specific parameter settings that enable the machine to create adesired scent effect at a particular location (e.g., a room of abuilding). Determining the parameter settings to create a desired scenteffect requires consideration of, for example, the machine's environmentat the scent location (e.g., how close is the machine to a window, avent, or a door), the scent type, etc. The base scent setting may, forexample, refer to an optimal cycle time (e.g., 120 seconds) and/or dutycycle (e.g., 50%) for the particular machine that achieves the desiredscent effect at the scent location. In some cases, the base scentsetting may additionally or alternatively refer to other variableparameters of the machine, such as fan speed, nozzle pressure,compressor power, etc., that ultimately have an impact on the scentlevel.

In some implementations, the base scent setting is determined at thetime of installation of the machine at the scent location. In otherimplementations, the base scent setting may be determined prior to orsubsequent to installation. The determined base scent setting may be setby a user at the machine through user interactions with the machineitself (in implementations in which scent setting controls are includedin the machine) and/or may be set by a user through interactions with auser device 108. The base scent setting may be set at the time ofinstallation as part of the installation process and/or may be setsubsequent to installation of the machine as part of a later machineinitialization process. After being set, the base scent setting may besubsequently changed by a user at the machine through interactions withthe machine itself and/or by a user (local or remote to the machine)through interactions with the user device 108. In some cases, thecentral controller and/or the machine may require additional usercredentials for changing the base scent setting. For example, only auser with systems administrator privileges may be able to change thebase scent setting.

The central controller 102, which can be, for example, a rack mountableserver, is configured to maintain a database that includes informationabout each scent delivery unit 104 in the system 100. This informationcan include, for example, the physical as well as network location ofeach scent delivery unit 104 along with information about the type ofscent it contains. The database can also include, for example,information about a base scent setting of each scenting unit 104, asspecified by, for example, its cycle time and duty cycle. In someimplementations, information about the base scent setting of each scentunit 104, or any other machine-specific parameter, may be directlystored in or otherwise accessed by each scent unit 104. Under thisimplementation, each scent unit 104 may send or otherwise makeaccessible the machine-specific parameters to the central controller 102upon request.

The central controller 102 may also be configured to maintain a masterschedule that can be accessed by the user and that incorporates multiplescheduled events for each scent delivery unit 104. Each scheduled eventspecifies control logic to activate and deactivate the one or more scentdelivery units 104 during desired one or more time periods. The controllogic may activate and deactivate the one or more scent delivery units104 individually and/or in user-defined groups. In one implementation,the master schedule may refer to an aggregate of all scheduled eventsfor all scent delivery units within the network controlled system 100.The master schedule may be stored in or otherwise accessible through thecentral controller 102. In some cases, the master schedule may refer toa group of particular scheduled events, for example, all scheduledevents pertaining to scent delivery units positioned in a certainlocation (e.g., a particular building, a particular floor of a building,or a particular room or set of rooms in a building). In some cases, themaster schedule may include a collection of other master schedules.

To program a desired scenting schedule for the one or more scentdelivery units 104, a user can access the central controller 102 throughuse of the user device 108. The user device 108 may be, for example apersonal computer or a mobile device. In some implementations, the userdevice 108 is configured to communicate with the central controller 102through the network 106. In some implementations, the user device 108may additionally or alternatively access the central controller 102 bydirectly connecting to it without going through a network. Notably,while only one user device 108 is shown in FIG. 1, it should beunderstood that the system 100 can include multiple user devices 108,each of which enables a different user to communicate with the centralcontroller 102 to, for example, schedule one or more scenting events.The one or more scenting events are compiled by the central controller102 into a master schedule, which, in some implementations, may bepresented in whole or in part to the user of the user device 108 tofacilitate event scheduling.

The central controller 102 can include a user interface component thatallows the user to make changes to the master schedule and to access andupdate the database that includes information about each scent deliveryunit 104. In some implementations, the user interface component is auser interface web component that allows the user to make changes to themaster schedule and to access and update the scent delivery unitdatabase over the World Wide Web.

Based on the master schedule and the machine-specific informationavailable from the database, the central controller 102 can generate aset of machine-specific command data that corresponds to the desiredschedule. In one implementation, the central controller 102 generates,for each scent delivery unit 104, command data that is made up of aseries of on and off commands, where the frequency and duration of theon and off periods are based on the specified cycle time and duty cycleof each scenting unit, and transmits this data in real-time to thecorresponding scent delivery units. In response to this command data,each scent delivery unit 104 may simply turn on (i.e., deliver scent) inreal-time in response to and upon receiving a “turn ON” command andturns off (i.e., not deliver scent) in real-time in response to and uponreceiving a “turn OFF” command. Alternatively, the central controller102 may generate, for each scent delivery unit 104, a single turn ONcommand that corresponds to a scheduled activation and a single turn OFFcommand that corresponds to a scheduled deactivation. Under this type ofcontrol scheme, the scent delivery unit 104 may be configured toconstantly deliver scent during the period of activation, instead ofbeing turned on and off successively according to a duty cycle.

In other implementations, the central controller 102 can generate andtransmit command data that contains all required information for eachscent delivery unit 104 to perform as scheduled (e.g., transmits commanddata directing the unit to activate from 1:30 pm to 3:30 pm onWednesday, July 7th using a scent cycle time of 300 seconds and a 50%scent duty cycle). Each scent delivery unit 104 can receive andindependently act on a command to activate during a certain time periodat a specified scent level. Notably, in these implementations, the scentdelivery units 104 may have additional processing and memorycapabilities that enable them to process the more complex command datareceived from the central controller 102. Also, the scent delivery unit104 may be configured to synchronize its activation and deactivationschedules with those of the other scent delivery units 104.

Because each scent unit 104 may be associated with an optimal base scentsetting (e.g., cycle time and duty cycle), the user may schedule thedesired activation time of a unit, for example by creating a scheduledevent, without having to specify any of the parameters of the base scentsetting (e.g., cycle time and/or the duty cycle) for the scheduledevent. In this case, the central controller 102 may simply generatecommand data to reflect the desired activation time and the base scentsetting associated with the unit. In other cases, the generated commanddata may not include any information about the base scent settingparameters (e.g., cycle time and/or the duty cycle), with the unititself being configured to simply operate during the desired activationtime according to its optimal base scent setting.

In other implementations, the user may wish to create a scheduled eventthat deviates from the base scent setting for a machine. For example,the user may walk through the lobby during a particular scheduledactivation time and feel that the scent provided by a particular machineis too weak (i.e., should be perceived as being stronger). In this case,the user may access the central controller 102 and update the base scentsetting for the responsible machine to, for example, have a higher scentlevel (e.g., by increasing the duty cycle). This, however, may impactother scheduled scenting events that use the same machine, which may beundesirable. Alternatively, the user may access the central controller102 and update just the particular scheduled event during which thestronger scent is desired. Notably, unlike sound, light, temperature,etc., which have a desired setpoint that can be easily quantified (e.g.,decibel, lumen, degree Celsius, etc.), the desired perception of scentmay be harder to define. Accordingly, instead of setting an absolutescent setpoint, the user may, for example, associate the particularscheduled event with a positive or negative scent level bias to increaseor decrease, respectively, the associated duty cycle relative to thebase scent setting. Other scheduled events that control the same machinewithout indicating this bias will continue to operate according to thebase scent setting associated with the machine. The scheduled events mayindicate the bias either directly or indirectly.

As noted above, the base scent setting of each machine (e.g. cycle timeand duty cycle) may be set at the time of installation and may beoptimized in view of the machine's location, scent type, etc. Forexample, the manufacturer, at the time of installation, may carefullyanalyze the particular scenting environment—through trial and error,internally developed metrics, instrumented analysis, or use of aprofessional perfumer, just to name a few methods—to come up with theideal base scent setting for a particular machine. However, duringnormal usage, a user may want to deviate from the base scent settingdepending on, for example, dynamic variables specific to a given scentevent (e.g., number of people in the room during the event, HVACsettings during the event, etc.). Such dynamic variables may not havebeen present or otherwise considered during the time of installation. Assuch, the user may schedule a desired scent event in consideration ofsuch dynamic variables by simply determining the appropriate bias valuerelative to the base scent level—without altering the base scent levelitself.

In other implementations, the user may wish to change, for example, thescent levels (e.g., by changing the duty cycle) of multiple machines,where each machine may be configured, via the base scent setting, tooperate at different cycle times and/or duty cycles. In thisimplementation, as detailed further below, the user may indicate asingle scent level bias that will correspondingly alter the scent levels(e.g., duty cycles) of the multiple machines while preserving their basescent settings. In most cases, a duty cycle of the machines may bevariable in the range between around 5% to around 95%.

FIG. 2 is a flowchart of an example process 200 in which a system mayalter a scent level of a scent delivery unit during a particularactivation period without permanently altering the associated base scentsetting. Briefly, the process 200 includes receiving input addressingthe activation of a scent delivery unit along with an associated scentlevel bias (202), and retrieving the base scent setting associated withsaid scent delivery unit (204). Based on the received input and theretrieved base scent setting, the system generates command data toactivate the scent delivery unit by applying the received scent levelbias to the retrieved base scent setting (206). The generated commanddata is then sent to the scent delivery unit (208).

Here, generating command data may include generating a set ofmachine-specific instructions that incorporates all scheduled events fora given machine and instructs said machine when to turn on and off. Insome implementations, the generated command data may be stored in amachine-specific table of instructions that does not lead to conflictingmachine behavior. In some implementations, generating command data mayinclude updating and/or revising the master schedule of events toeliminate instances of conflicting machine behavior.

Sending command data may include transmitting the generated command datato the one or more scent delivery units across a network (e.g., network106). In some implementations, the command data may be sent in real-timeas they are generated. Alternatively, or additionally, the command datamay be sent at predetermined time intervals, e.g., once every minute. Insome cases, the command data may be sent in response to and uponreceiving instructions from the user. In other cases, the command datamay be sent in response to and upon receiving a query for instructions,e.g., from the scent delivery unit.

In one implementation example, the process 200 of FIG. 2 may beimplemented by the system 100 of FIG. 1. In this implementation, thecentral controller 102 may receive input addressing the activation of ascent delivery unit under a scent level bias (202) when the userschedules a scenting event that includes the scent delivery unit andfurther indicates that a bias should be applied for the particularevent. For example, a user-entered scheduled event may indicate that thefirst scent delivery unit should be activated every Monday from 9:00 amto 5:00 pm under a +15 bias. Particular values that may be associatedwith the bias will be discussed further below; however, the positivevalue in this example indicates that the user desires a higher scentlevel during the indicated activation period. The higher desired scentlevel may indicate that the user wants to perceive a stronger scentduring the noted activation period compared to other activation periodsfor the same machine. Alternatively, or additionally, the higher desiredscent level may indicate that the user wants to perceive the samestrength of the scent during the noted activation period as in otheractivation periods for the same machine, but that particular conditionsof the scenting environment during the noted activation period require ahigher scent level to achieve the same perceived effect. For example,there may be higher foot traffic during the noted activation period. Insome cases, the user-entered scheduled event may indicate that a groupof scent delivery units should be activated as scheduled. Either way,before the scent delivery unit can be activated according to the userinput, the central controller 102 will need to determine what commanddata should be sent to the scent delivery unit.

In operation 204, the central controller 102 retrieves the base scentsetting of the scent delivery unit from operation 202. Because the scentlevel bias information received in operation 202 indicates a relativeincrease/decrease as opposed to an absolute setpoint, the centralcontroller 102 may need to know the base scent setting in order togenerate the appropriate command data. In some implementations, thecentral controller 102 may include or otherwise have access to adatabase that stores the information pertaining to each scent deliveryunit, including its base scent setting. In some cases, the centralcontroller 102 may obtain such information directly from the individualscent delivery units. In some cases, each scheduled event may bepre-loaded with the base scent setting information for each machineincluded in the scheduled event, and this information may be passed ontothe central controller 102 along with the received input addressing themachine's activation.

The central controller 102 will proceed to generate, in operation 206,command data to activate the scent delivery unit in a manner thataccounts for the scent level bias. For example, if the centralcontroller 102 receives input, in operation 202, from a newly enteredscheduled event indicating that a particular scent delivery unit shouldbe activated daily from 1:00 pm to 6:00 pm under a scent level bias of+15, and if the central controller 102 knows, from operation 204, thatthis particular scent delivery unit is associated with a base scentsetting having a cycle time of 300 seconds and a duty cycle of 50%, thenthe central controller 102 will generate command data that applies the+15 bias to the duty cycle of 50%. In this example, the centralcontroller 102 may simply add 15 percentage points to the base dutycycle of 50%. Accordingly, the command data will indicate that the notedscent delivery unit should activate daily from 1:00 pm to 6:00 pm, andthat during this activation period, the scent delivery unit should turnon and off successively for periods of 195 seconds and 105 seconds,respectively.

In some implementations, the central controller 102 may use anarithmetic function in applying the scent level bias to the base scentlevel. For example, a +15 bias may simply be added to a base duty cycleof 50%, thereby yielding a revised duty cycle of 65% (i.e., 50+15) forthe generated command data. Alternatively, or additionally, the centralcontroller 102 may use a geometric function in applying the scent levelbias to the base scent level. For example, a +15 bias may indicate apercentage increase to the base duty cycle of 50%, thereby yielding arevised duty cycle of 57.5% (i.e., 50×1.15) for the generated commanddata.

In some implementations, the scent level bias, as inputted by the user,may be applied in a different manner by the central controller 102depending on a machine-specific parameter and a pre-defined algorithmrelated to said parameter. In one implementation, prior to being appliedto the base scent level, the scent level bias may be scaled up or downby a known amount in accordance with an algorithm. For example, amachine having one type of a scent may have the full bias applied to itsbase scent level, while a different machine having a different type of ascent may have only half of the bias applied to its base scent level. Insome cases, the scaling factor for the scent level bias may varydepending on the base scent level. For example, the scaling factor maybe inversely proportional to the base scent level. In otherimplementations, the scaling factor for the scent level bias may varyaccording to a known calibration curve for each machine and/or scenttype.

As noted above, the duty cycle may be varied between around 5% to around95%. In some cases, each scent delivery unit may be associated with itsown range of duty cycle. In either case, if applying a scent level biasto the base scent level of a particular machine would result in thatmachine's duty cycle going beyond the specified range, the centralcontroller 102 may instead generate, for that particular machine,command data that corresponds to the maximum or minimum specified dutycycle. In some cases, when a scheduled event controls activation ofmultiple machines under a single scent level bias, the centralcontroller 102 may generate command data for all machines based on areduced scent level bias that would not push any of the machines beyondthe specified range of duty cycle.

FIGS. 3 and 4 illustrate a series of exemplary graphical user interface(GUI) windows 300, 400, and 402 associated with the scent deliverysystem 100. The graphical windows 300, 400, and 402 may be provided bythe user interface component of the central controller 102 and may beaccessed by one or more users over, for example, the World Wide Webusing a browser application resident on one or more of the user devices108.

Referring to FIG. 3, the graphical window 300 illustrates how datapertaining to a particular scent delivery unit may be entered. The datamay be maintained in a database contained within or otherwise accessibleto the central controller 102 and may be accessed and/or updated by oneor more users, for example, through use of one or more of the userdevices 108 across the network 106. The particular types and styles ofGUI input elements, i.e., entry boxes, check boxes, pull-down menus,etc., as depicted in the exemplary windows are for illustrative purposesonly and may be altered as necessary depending on system requirements,user preferences, scenting environment, etc.

The graphical window 300 illustrates data entry pertaining to a scentdelivery unit named “Machine_A,” as indicated in entry box 302. In thesame window 300 or in another interface, the name Machine_A may furtherbe associated with a network address or the like such that the centralcontroller 102 may send command data thereto in order to controlMachine_A as dictated by the master schedule.

In pull-down box 304, the scent type associated with Machine_A may beidentified. While the actual scent type that Machine_A is able to emitwill be determined by what particular scent or scents are physicallyinstalled in the machine, entering the scent information here willenable the central controller 102 to keep track of which machine isconfigured to which scent. This information may inform themachine-relatedness determination noted below.

In similar fashion, pull-down box 306 can be used to identify theparticular location associated with Machine_A. While the actual locationof Machine_A is determined by where the machine is physically located,entering the scent information here will enable the central controller102 to keep track of where each machine is located. This informationalso may inform the machine-relatedness determination noted below.

Entry boxes 308 and 310 may identify, respectively, the desired scentcycle time and scent level percentage for Machine_A. Here, scent cycletime refers to the period of time during which one on-off cycle occurswhile scent level percentage refers to the percentage of time during thecycle time in which the machine is turned ON (i.e., duty cycle). In somecases, data entries 308 and 310 indicate a base scent setting for thespecified delivery unit that reflects an optimal setting for theparticular unit. In some cases, the base scent setting for each machinemay be determined automatically by the central controller 102. Forexample, the particular scent type and/or location as selected inpull-down boxes 304 and 306 may be pre-associated with a correspondingbase scent setting, the information regarding which the centralcontroller 102 may be configured to store or otherwise access.

Check box 312 may be used to indicate whether the associated scentdelivery unit, in this case Machine_A, is enabled. For example, checking“NO” for check box 312 may effectively take Machine_A offline, allowingthe central controller 102 to ignore any input concerning the activationof Machine_A. A user may not want a unit to be enabled, for example,during repair of the unit and/or during scent cartridge replacement.

Check box 314 may be used to indicate a mode of operation, or run mode,of the particular machine. Here, “automatic” may refer to the mode inwhich the machine is operated in accordance with the master schedule asmaintained by the central controller 102. Accordingly, Machine_A in thiscase will activate and deactivate based on conflict-free command datagenerated by the central controller 102. Setting the run mode to “ON” or“OFF” may be akin to manual override of the machine. In other words,selecting ON for entry 314 will immediately activate the machineregardless of the activation/deactivation schedule contained in themaster schedule. Likewise, selecting OFF for entry 314 will immediatelydeactivate the machine regardless of the master schedule. During amanual ON or OFF period, scheduled events to the contrary may not bepermitted by the central controller 102. In other words, a manualcontrol will have, under this scheme, priority over any previously orsubsequently added scheduled events.

As with scheduled events, immediate requests for activation and/ordeactivation may be sent by the central controller 102 as command data.In some cases, “automatic” may be a default setting for check box 314 towhich the selection will revert back after a period of time. Forexample, any selections of either ON or OFF may reset back to“automatic” every day at midnight, thereby returning the machine toautomatic, scheduled control. Accordingly, while disabling the machinevia entry 312 and manually turning off the machine via entry 314 canboth effectively take the machine offline, turning off the machine viaentry 314 will allow it to automatically revert back to automatic modeafter a period of time.

Referring again to the graphical window 300 in FIG. 3, pull-down box 316may be used to indicate a group to which a particular machine maybelong. As discussed further below in relation to the schedulingprocess, grouping multiple machines into a group may allow the user toquickly schedule a larger number of machines without having to enter aseparate event for each machine. Alternatively, or additionally, aseparate interface may be used to define various groups and the machinescontained therein.

Pull-down box 318 may be used to input information regarding relatedunits, which will be discussed further below. Alternatively, oradditionally, an additional user interface may be provided to allow theuser to choose which units are related. Entry box 320 may be used toinput information regarding fail safe time, which will be discussedfurther below.

In some implementations, any authenticated user may access the window300 and change the data corresponding to all or some of the GUI inputelements in the window 300. In other implementations, only anauthenticated system administrator user can access the window 300 andchange the data corresponding to all or some of the GUI input elementsin the window 300. In these implementations, the other authenticatedusers may not be allowed to access the window 300, may be allowed toaccess the window 300 but may not be allowed to change the datadisplayed in the windows, or may be allowed to access the window 300 butmay only change the data corresponding to a subset of the GUI inputelements (e.g., can only change the run mode using check box 314).

FIG. 4 shows an example GUI that includes graphical windows 400 and 402for creating scheduled events. In some implementations, anyauthenticated user that wishes to schedule a scenting event may interactwith windows 400 and 402 using a user device 108 to schedule a scentingevent. In other implementations, only an authenticated systemadministrator user is able to interact with windows 400 and 402 using auser device 108 to schedule a scenting event. In some implementations,any authenticated user that wishes to schedule a scenting event mayinteract with windows 400 and 402 using a user device 108 to providescenting event schedule data to the central controller 102 but onlyauthenticated system administrator users may interact with window 300 toprovide unit-specific information to the central controller 102.

As illustrated, the graphical window 400 creates a scheduled eventcalled “Schedule 1” (404) for Machine_A while the graphical window 402creates a scheduled event called “Schedule 2” (424) for the sameMachine_A. The user may create additional scheduled events as needed forMachine_A as well as other scent delivery units in the system 100 byopening a scheduled event interface for each new event desired. In thisexample, information pertaining to Machine_A corresponds to informationentered for the same machine through interactions with the graphicalwindow 300 in FIG. 3.

In further detail, by making selections in event type check boxes 406,426, the user can indicate the desired type of a scheduled event. Forexample, a “calendar” type event can allow the user to choose days ofthe month as well as particular times of day during which machine ormachines identified in pull-down boxes 410, 430 should be activated. A“weekly” type event, on the other hand, can allow the user to choosedays of the week as well as particular times of day during which machineor machines identified in pull-down boxes 410, 430 should be activated.A weekly event, because it can be repeated week to week, may also bereferred to as a recurring event. As illustrated in the graphicalwindows 400, 402, selecting the “weekly” option in entry 406 can causethe windows 400, 402 to display check boxes 412, 432 that allow the userto specify days of the week during which the machine or machines shouldbe activated. The “on time” entries 414, 434 and “off time” entries 416,436 indicate, respectively, the time at which the machine or machinesshould be activated and at which they should be deactivated. In somecases, each graphical window may include multiple on/off times tospecify multiple activation periods in a single day.

In addition to allowing the user to specify operating conditions forindividual machine or machines, group/unit check boxes 408, 428 canallow the user to specify operating conditions for a group of machines.For example, choosing “unit” in entry sections 408, 428 may causepull-down menus 410, 430 to list all networked scent delivery units. Asdiscussed further below with respect to FIG. 8, choosing “group” inentry sections 408, 428 may cause pull-down menus 410, 430 to insteadlist all groups of machines previously identified. This way, multiplescent delivery units associated with a group (e.g., a “Lobby Group” thatincludes all machines located in the lobby) may be quickly scheduledthrough a single scheduled event.

The bias setting entry boxes 418, 438 allow the user to input thedesired scent level bias. A scent level bias of 0 indicates that thescheduled event should proceed at a scent level (e.g., duty cycle)associated with the base scent setting. A positive or a negative scentlevel bias indicates that the scheduled event should proceed at a scentlevel that is higher or lower, respectively, in relation to the scentlevel associated with the base scent setting. In some implementations,the numerical value of the scent level bias may correspond to apercentage change to the duty cycle associated with the base scentsetting, which may be applied either arithmetically and/or geometricallyas discussed above. In some implementations, the numerical value of thescent level bias may be an arbitrary value whose specific effects on thescent level may be determined by the central controller 102, or in somecases by the scent delivery units themselves, according to a pre-definedcontrol logic. In some implementations, the numerical value of the scentlevel bias may correspond to a time value, for example a time change inseconds to be applied to a length of the ON cycle. Alternatively oradditionally, the scent level bias may be applied to fan speed, nozzlepressure, compressor power, and/or other machine-specific parametersthat may in other ways influence total number of scent particlesreleased in an environment during a given amount of time.

Check boxes 420, 440 may be used to indicate whether or not the instantscheduled event is an anti-event, as will be discussed further below.

FIG. 5 shows a graphical representation of two scheduled events 500, 502as created through the exemplary GUI windows 400, 402 (FIG. 4).Reference is also made to information about Machine_A as mentioned inthe example of FIG. 3. In some implementations, the central controller102 is able to provide event-specific graphical representation to a userdevice 108 to enable the device 108 to display a GUI to the user thatincludes figures graphically depicting each scheduled event. Suchfigures enable a user to quickly, at-a-glance, see and compare thevarious scheduled events.

As shown in FIG. 5, scheduled events Schedule 1 and Schedule 2 include,respectively, event-specific machine data 504, 506. Representation ofevents 500, 502 also indicate the scent level bias that was included inthe scheduled events, in this case 0 and +15, respectively. Here, themachine data 504, 506 represent information that the central controller102 will use to generate appropriate command data. As such, data 504,506 reflects an application of the scent level bias to the base scentsetting. For example, the central controller 102 may generate commanddata for Machine_A, which has a base duty cycle of 50% (FIG. 3), thatcorresponds to a 50% duty cycle in Schedule 1 and a 65% duty cycle inSchedule 2. The base scent setting for Machine_A in either of theexemplary scenarios will remain unchanged (i.e., scent time of 120 sec.and duty cycle of 50%).

FIG. 6 shows a plot 600 illustrating duty cycle-based scent cycling thatwould occur during an activation period of Machine_A under Schedule 1(602) and under Schedule 2 (604). As shown, a positive scent level biashas the effect of increasing the ON time for each cycle while decreasingthe OFF time.

In some implementations, the central controller 102 may automaticallyadd a period of rest after an activation period to, for example, allowany lingering scent to sufficiently dissipate before scent from the nextevent is emitted. For example, referring to Schedule 2 form FIG. 4, thecentral controller 102 may automatically add a rest period at 9 pm(e.g., 2 minutes) so that subsequent scenting events taking place in thesame location are delayed. As such, a scent event scheduled to run from9 pm to 11 pm in the same location as Schedule 2 may be revised toinstead run from 9:02 pm to 11 pm. This way, the added rest time mayallow scent particles from Schedule 2 to sufficiently dissipate from thescenting environment before scent particles from the next scheduledevent are introduced into the same space.

A length of the automatically added rest period, as described above, mayvary according to a multitude of factors, including, but not limited to,scent type, dissipative properties of scent particles, length ofactivation period, type of room being scented, etc. Based on one or moresuch factors, the central controller 102 may be configured toautomatically calculate the appropriate rest period using a predefinedalgorithm. For example, a small room with high foot traffic (e.g.,lobby) may require less rest period than a large open space (e.g.,ballroom). Similarly, a short activation period may require less restperiod than a long activation period. Additionally, or alternatively,the central controller 102 may be configured to automatically calculateand implement the appropriate length of rest based on the scent levelbias of the preceding event. For example, a scenting event operatedunder a high positive bias may require a longer rest period compared toan event operated under a high negative bias.

Referring to FIG. 7, a GUI window 700 shows multiple scent deliveryunits that may be associated with a single group, in this case Group1.Referring also to FIG. 8, windows 800, 802 illustrate how two scheduledevents, Schedule 1 and Schedule 2, may be created by designating groupsof machines, instead of individual machines as illustrated in theexample of FIG. 4. Each scent delivery unit may be associated withmultiple groups.

To create scheduled events for groups, entries 804-840 in graphicalwindows 800, 802 may be completed in much the same manner as describedabove with respect to windows 400, 402 in FIG. 4. Check boxes 808, 828should, however, indicate that a “group” is being selected instead of a“unit.” Making this selection in boxes 808, 828 will cause pull-downboxes 810, 830 to list all groups as identified by the centralcontroller 102. In this example, “Group1” may be chosen in entries 810,830 to indicate that all machines listed in window 700 should becontrolled for this scheduled event. The bias setting entry 818, 838 maybe completed as before to indicate the desired scent level bias for allmachines in the group.

FIG. 9 shows a graphical representation of two scheduled events 900, 902as created through the exemplary GUI windows 800, 802 (FIG. 8).Reference is also made to information about individual units of Group1as given in FIG. 7.

As shown in FIG. 9, scheduled events Schedule 1 and Schedule 2 include,respectively, event-specific group data 904, 912, each of which containsevent-specific machine data 906-910 and 914-918, respectively.Representation of events 900, 902 also indicate the scent level biasthat was included in the scheduled events, in this case 0 and +15,respectively. Here, the group data 904, 912 represent information thatthe central controller 102 will use to generate appropriate commanddata. As such, the group data 904, 912 reflect an application of thescent level bias to the base scent settings of each machine in thegroup.

Referring to FIG. 10, a block diagram 1000 illustrates an exemplaryimplementation of the central controller 102 (FIG. 1). As shown,exemplary central controller may be largely divided into two components:scheduler 1002 and database 1004. Here, the scheduler 1002 is mainlyresponsible for the scheduling and controlling of individual scentdelivery units while the database 1004 stores or otherwise makesaccessible data pertaining to each scent delivery unit in the system.For example, contents of the window 300 (FIG. 3) and window 700 (FIG. 7)may be stored and maintained in the database 1004.

In further detail, the scheduler 1002 can include a schedule controlsection 1006 and a scent delivery unit control section 1010. In thisimplementation, the schedule control section 1006 is configured toreceive the desired scheduling information from the user, e.g., via oneor more scheduled events, and communicate with the database 1004 asneeded to retrieve data pertaining to the scent delivery unit referredto in the one or more scheduled events. For example, in response to theentry of the scheduled event shown in graphical window 400 (FIG. 4), thescheduler control section 1006 may query the database 1004 to find outthe network location of Machine_A.

The schedule control section 1006 may be configured to perform abias-applying process, such as process 200 (FIG. 2), in order togenerate command data that changes the instant scent level of scentdelivery units without changing their base scent settings. In oneimplementation, the generated command data may be in the form of a listof instructions for each scent delivery unit in the networked system100. For example, in reference to FIG. 4, the list of instructions forMachine_A under Schedule 1 may include (i) turning on at 9:30 am and(ii) turning off at 2:30 pm. Similarly, referring again to FIG. 4, thelist of instructions for Machine_A under Schedule 2 may include (i)turning on at 3:00 pm under a +15 scent level bias and (ii) turning offat 9:00 pm. The schedule control section 1006 may then output this listof instructions to an out table 1008. The out table 1008 can beconfigured to store the updated list of instructions for each machine inthe system. The out table 1008 may be updated following the addition,deletion, and/or revision of a scheduled event. Alternatively, oradditionally, the schedule control section 1006 may update the out table1008 periodically according to a pre-determined schedule (e.g. everyminute) regardless of whether any changes were made to the scheduledevents.

In another implementation, the out table 1008 may include real-timeinstructions for the scent delivery units. That is, the list ofinstructions may simply instruct the machine to, for example, turn onand start operating at the given cycle time and duty cycle. In response,the machine may continue to operate at the given duty cycle until asubsequent instruction received from the out table 1008 instructs themachine to turn off. In this implementation, the scent delivery unitsmay require minimal intelligence and functionality.

The scent delivery unit control section 1010 may be configured todirectly implement a communication protocol between the centralcontroller and the individual scent delivery units. For example, thescent delivery unit control section 1010 may be configured to simplyread off instructions from the out table 1008 and broadcast them one byone to each of the network-controlled scent delivery units. In somecases, the scent delivery unit control section 1010 may be configured toverify proper data communication by receiving verification signals fromthe individual scent units. Such verification signals may be receivedand stored in an in table 1012. The in table 1012 may send or otherwisemake accessible the verification information to the schedule controlsection 1006, such that a user may receive real-time status updates ofeach machine out in the field.

As noted above, a master schedule can refer to an aggregate of allscheduled events and may be maintained by the central controller 102. Inone implementation, master schedule data is updated by user input atunpredictable times (e.g., when the user decides to add/update/remove ascheduled event). Updated master schedule data may then be processed bythe schedule control section 1006 in real-time (e.g., once every fewseconds), in response to and upon detection of user input of a new ormodified scheduled scenting event, or at predetermined time intervals(e.g., once every 5 minutes) to generate/update non-conflictingmachine-specific instruction tables. The machine-specific instructiontables are a list or grouping of instructions with correspondingexecution time information for a specific machine. The machine-specificinstruction tables for all machines in the system may be aggregated intothe out table 1008. The instructions for a corresponding machine'soperation included in a particular machine-specific instruction tablemay indicate operations that need to be performed by the machine over arelatively long period of time (e.g., a day, a week, or a month).

In one implementation, the scent delivery unit control section 1010receives the out table 1008, which contains the non-conflictingmachine-specific instruction tables, and sends out each machineinstruction (e.g., “turn on” instruction) at its appropriate time toeach respective machine based on the out table 1008 (e.g., by processingthe table). The delivery of an instruction may occur in real-time (e.g.,a “turn on” instruction is sent in real-time, which results in themachine turning on in response to and upon receipt of the instruction).This implementation allows scent delivery units with little intelligenceto be used. However, this implementation may also have greatersensitivity to connection failures, given that it may require arelatively continual and uninterrupted connection between the centralcontroller and the units to operate properly.

In an alternative implementation, delivery of instructions from thescent delivery unit control section 1010 may occur ahead of time (e.g.,a “turn on at 6 pm” instruction being sent at 5 pm). In some cases, thescent delivery unit control section 1010 may simply send thenon-conflicting machine-specific tables (or the updated portions of thesame) to each of their respective machines for processing. In thesecases, the machines are intelligent units able to process the tableswith their own internal and synchronized clocks. This implementation maybe less sensitive to connection errors because the instructionsgenerally do not need to be continually sent in real-time for properoperation. This implementation, however, requires more intelligent scentdelivery units that have additional processing capabilities to processthe instructions at their appropriate times in synchronicity with theother scent delivery units (e.g., scent delivery units that each havetheir own clock that may include circuitry to synchronize the clock withthe clocks of the other scent delivery units and that each have theprocessing capabilities to interpret and execute more complex receivedinstructions).

In some implementations, updated master schedule data may be processedby the schedule control section 1006 in real-time (e.g., once every fewseconds) in response to and upon detection of user input of a new ormodified scheduled scenting event, or at predetermined time intervals(e.g., once every 5 minutes) to generate/update a second version of themaster schedule that is non-conflicting. Notably, in someimplementations, this second version may be saved as separate data fromthe conflicting master schedule data to allow the conflicting masterschedule data to be preserved intact for subsequent processing based onnew user input. In other implementations, the second version mayoverwrite the master schedule data and become a new master schedule dataused for future processing based on new user input. Theseimplementations, however, may be less preferable in that they may limitthe ability to recover the original user-inputted scenting event datawhen conflicts subsequently change (e.g., go away) as a result ofsubsequent user input.

In some implementations, the updated, non-conflicting master scheduledata may be sent directly by the scent delivery unit control section1010 to each scent delivery unit for processing. Each scent deliveryunit in this implementation has intelligence to directly process themaster schedule at clock times that are synchronized with that of theother units.

In some implementations, the schedule control section 1006 may processthe updated, non-conflicting master schedule data (i.e., the secondversion of the master schedule data) to generate non-conflictingmachine-specific instruction tables that are subsequently sent to eachrespective machine. Here, no conflict-resolving processes are requiredto generate the machine-specific instruction tables since the masterschedule itself has been updated to be conflict-free. As describedabove, such machine-specific instructions may be sent out in real-timeto less intelligent scent delivery units or may be sent out ahead oftime to more intelligent scent delivery units.

FIG. 11 is a flowchart of an example process 1100 in which the centralcontroller may command scent delivery to activate under a scent levelbias. While process 1100 may be implemented by various systems,explanation of the exemplary process 1100 is given in relation to thecontroller described in FIG. 10.

The schedule control section 1006 is configured to receive inputaddressing the desired activation of a scent delivery unit under a scentlevel bias (1102). For example, as illustrated in graphical window 402(FIG. 4), a scheduled event that includes the desired scent level bias(i.e., bias setting), may be received by the schedule control section1006.

Based on the received input and the retrieved base scent setting (1104),the schedule control section 1006 generates command data to activate thescent delivery unit by applying the received scent level bias to theretrieved base scent setting (1106).

The generated command data is subsequently sent to the scent deliveryunit by the scent delivery unit control section 1010 (1108). In somecases, the command data may be in the form of network packets or othersuitable data formats that can be communicated across the network 106.The one or more scent delivery units 104 are configured to receive suchdata (1110) and operate (i.e., turn on or off) based on the receiveddata (1112). In some implementations, the one or more scent deliveryunits may send a confirmation signal back to the scent delivery unitcontrol section 1010 (1114), to indicate, for example, that the sentdata has been properly received and/or that the machines are functioningproperly. The scent delivery unit control section 1010 may then updatethe current status of each machine by, for example, appropriatelypopulating the in table 1012 (1116). In some cases, the command data maybe in the form of a signal that is a waveform and may include multipletransitions in signal level that correspond to changes in the on/offstate of the corresponding scent delivery unit. In some cases, thesignal may be a pulse that corresponds to a change in the on/off stateof the corresponding scent delivery unit.

FIG. 12 shows an exemplary scent delivery unit 1200. The scent deliveryunit 1200 may be used as a standalone system, or may be used as part ofthe networked scent delivery system 100. Briefly, the scent deliveryunit 1200 includes a diffusion head 1202 that is mounted on a cartridgebottle 1204. Scented liquid is stored within the bottle 1204 and can beatomized into the atmosphere via the head 1202. The diffusion head 1202may comprise a venturi-type atomizer.

In one implementation, each scent delivery unit 104 includes a scentreservoir and an atomizing device in fluid communication with the scentreservoir. In one example, the scent reservoir is a cartridge bottlecontaining scented liquid, for example a fragrant oil mixture having adesired scent for the particular scent delivery unit 104. The atomizingdevice can be, for example, a venturi-type atomizer that uses a highvelocity airstream generated within a control unit 1206 to draw in andatomize the liquid in the cartridge bottle 1204 into small particles(e.g., under 10 microns in diameter) that can be dispersed into the airvia a nozzle 1208. The control unit 1206 may include a network receiveror the like to receive command data sent by the central controller 102(FIG. 1).

FIG. 13 shows an alternative scent delivery unit 1300. The scentdelivery unit 1300 may be a canister type machine that includes awicking structure impregnated with fragrance material. Airflow throughthe scent delivery unit 1300, for example generated by an on-board fan,can help evaporate and release the fragrance into the environment.Control electronics, network receiver, and other electrical/mechanicalcomponents may be included within a casing of the scent delivery unit1300.

Scent delivery units 1200 and 1300 represent just two of many differenttypes of scent delivery technologies that may be used with the scentdelivery system 100. Other types of scent delivery technologies mayinclude evaporative systems based on natural convection. Evaporativesystems may use scents from fragrance carriers such as liquid fragranceoil suspended in porous media including, but not limited to,woven/non-woven fabrics, papers felts, wood-like materials, porousplastics, foams, sponges, screens and wool-like materials. In somecases, fragrant compounds used in evaporative systems may beincorporated in semi-solids such as gels or may be absorbed into theintermolecular structure of nonporous materials such as plastic beads,fibers, or films. Evaporative systems may release scent when fragrancecarriers/evaporative media contained therein are exposed to air. Scentdelivery technologies may also include forced convection-type devicesthat rely on forced convection produced by fans or directed compressedair (e.g., from pumps or pressurized tanks) to enhance the release ofscent from the above-noted evaporated media. Alternatively oradditionally, heat energy (e.g., radiant heat from a candle orconvective heat from a heated blower) may be incorporated to increasethe rate of fragrance evaporation. Scent delivery technologies may alsoinclude direct diffusion-type devices where fragrance compounds aredirectly diffused into the air through various forms of atomizers toproduce a wide range of desired particle sizes. An atomizer may be inthe form of hydraulic spray nozzles configured to directly releasehigh-velocity liquids, liquid-liquid impinging atomizers configured tocollide liquid streams, and air-liquid impinging atomizers such asbubble tanks, airblast atomizers, prefiliming atomizers, andventuri-type atomizers. An atomizer may be a mechanical atomizer thatrelies on spinning discs or vibrating structures, for example, todeliver scent. For example, piezoelectric transducers may be used toatomize liquid oils via ultrasonic surface wave effects, or through theuse of microscopically perforated vibrating mesh (VMT). In some cases,high voltage can be used in an electrospray device, where electrostaticforces can cause the expulsion and dispersal of tiny volumes of liquidfrom a single fine orifice or a brush like structure of multiple points.Notably, any scent delivery unit is configured to deliver scent at avariable scent level by being turned on and off successively accordingto a variable duty cycle if it delivers scent at a variable scent levelby being turned on and off successively according to a variable dutycycle, regardless of whether it is specially configured for suchoperation or whether it is instead designed for use without duty cyclevariations.

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made without departingfrom the spirit and scope of the disclosure.

For example, while the above-described implementations assume a singleunit or machine corresponds to a single, physical piece of equipmentthat produces a single scent (e.g., Unit A may correspond to a single,physical scent delivery machine that includes a single cartridge bottlecontaining a single Pineapple scent), it should be understood that inother implementations a single, physical piece of equipment may beconfigured to produce many different scents, either concurrently and/orserially, and, therefore, may correspond to multiple different of theabove-described machines or units (e.g., Unit A corresponds to the firstcartridge bottle of a single physical piece of equipment that contains aPineapple scent and Unit B corresponds to a second cartridge bottle ofthe same single physical piece of equipment that is configured toproduce a leather scent). Accordingly, in implementations in which asingle, physical piece of equipment may deliver different scents (e.g.,through different cartridges), the single, physical piece of equipmentmay be treated as if it were multiple of the above-described differentunits or machines. In such implementations, a machine may refer to thesingle, physical piece of equipment while a unit may refer to each ofthe corresponding above-described different units or machines that maybe collocated, sharing the same power and same HVAC, emitting adifferent, single scent, etc. Additionally, while the above-describedimplementations assume a scent delivery unit or a machine includes oneor more of the above-noted scent delivery technologies, it should benoted that the scent delivery unit or machine may correspond to anyelement, including hoses, nozzles, and orifices, that can deliver scentin accordance with a schedule maintained by the central controller.

In another implementation, a scent level bias may result in command datathat reflects a change to both the cycle time as well as the duty cycleassociated with a base scent setting of a particular scent deliveryunit. That is, applying a scent level bias to the base scent setting ofa particular scent delivery unit may include activating the unit underan altered duty cycle as well as under an altered cycle time. Forexample, a scent delivery unit having a base cycle time of 600 secondsand a base duty cycle of 50% might typically operate, without any scentlevel bias, by successively turning on for 300 seconds and turning offfor 300 seconds. In response to a scent level bias of +45, the commanddata for activating the unit may then indicate that the unit shouldoperate under a cycle of 570 seconds of ON time and 30 seconds of OFFtime, reflecting in this case increasing the duty cycle to 95% whilekeeping the cycle time the same. In some cases, however, the user mayprefer that this unit not stay on continuously for more than, as anexample, 540 seconds (i.e., maximum ON time), for example to preventoverheating. In such a case, the command data may be adjustedaccordingly to take into account both the +45 bias as well as the 540second maximum ON time. To achieve this, the command data may indicatethat the unit should operate under a cycle of 540 seconds of ON time and28.4 seconds of OFF time, reflecting in this case increasing the dutycycle time to 95%, as before, but also simultaneously decreasing thecycle time from 600 seconds to 568.4 seconds to satisfy the maximum ONtime requirement.

Similarly, in some cases, the user may prefer that the unit's ON time belonger than, as an example, at least 60 seconds (i.e., minimum ON time),for example to give the machine sufficient time to emit a discernibleamount of fragrance into the environment. In such a case, applying −45scent level bias to above example may result in command data indicatingthat the unit should operate under a cycle of 30 seconds of ON time and570 seconds of OFF time, reflecting in this case increasing the dutycycle to 95% while keeping the cycle time the same. To satisfy both thedesired scent level bias and the minimum ON time, the command data maythen indicate that the unit should operate under a cycle of 60 secondsof ON time and 1140 seconds of OFF time, reflecting in this casedecreasing the duty cycle time to 5%, as before, but also simultaneouslyincreasing the cycle time from 600 seconds to 1200 seconds to satisfythe maximum ON time requirement.

In some implementations, the user may prefer that the scent deliveryunit operate in accordance with minimum/maximum OFF time. In such cases,the cycle time may also be similarly varied as described above withrespect to minimum/maximum ON time.

In another implementation, the central controller 102 can includepre-determined logic to prevent scent delivery units that are “linked”or “related” to each other from being activated simultaneously. A scentdelivery unit, or machine, may be said to be related (or linked) toanother if a user makes a prior determination, for example, that thesetwo particular machines should not be activated at the same timeregardless of information contained in the scheduled events.

In an example scenario, a systems administrator may determine that scentdelivery unit A and scent delivery unit B, each of which is configuredto deliver a different scent to a same room, should not be activated atthe same time in order to prevent overscenting the room and exposing itsoccupants to unpleasantly high levels of scent. In this case, thesystems administrator may indicate to the central controller 102 thatunits A and B are related to each other. The pull-down box 320 (FIG. 3)may list all available scent delivery units that the systemsadministrator may designate as being related. Once units A and B aredesignated as being related, the central controller 102 may beconfigured to prevent conflicting events from proceeding as scheduled.An example of a conflicting event could be where a first scheduled eventindicates that unit A should be activated every Monday through Wednesdayfrom 9:00 am to 5:00 pm while a second scheduled event indicates thatunit B, which is related to unit A, should be activated every Wednesdaythrough Friday from 3:00 pm to 10:00 pm. In this case, the two eventsmay be said to be in conflict because an overlapping activation periodoccurs on every Wednesday from 3:00 pm to 5:00 pm.

In some implementations, in addition to or as an alternative to thesystem administrator directly indicating which machines are related, thecentral controller 102 may automatically identify any units that, forexample, share a location as being related. For example, the centralcontroller 102, upon receiving or otherwise accessing information thatunits A and B are both located in the same room, may automaticallydetermine that units A and B are related to each other. In someimplementations, the system administrator may manually set a preferencewith the central controller 102 that instructs the central controller102 to perform an automatic relatedness determination.

While the above example discloses an automatic relatedness determinationbeing performed by the central controller 102 based on determining thattwo units are collocated, the automatic relatedness determinationperformed by the central controller 102 (or the manual determination ofthe system administrator) may take into account one or more otherfactors in addition to or as an alternative to unit collocation. Forexample, scent delivery units that emit incompatible scents (e.g.,scents that are not pleasant when smelled at the same time) may bedefined or identified as being related. In another non-limiting example,scent delivery units that share a common power supply may be defined oridentified as being related, for example, to prevent the common powersupply from being overdrawn. In yet another non-limiting example, scentdelivery units that are installed in different locations but otherwiseemit scent to a same location (e.g., via the HVAC system) may be definedor identified as being related. In some cases, multiple machine-specificfactors may need to be considered to indicate relatedness. For example,two machines may be said to be related if they share the same locationbut are configured to emit a different scent, or alternatively the samescent.

In another implementation, the central controller 102 may allow a userto schedule an anti-event in much the same way that a regular scentingevent may be scheduled, with the anti-event capable of having priorityover regular events. This may be desirable, for example, if the userwishes to schedule ahead of time one or more periods of time duringwhich a particular location within the scenting environment will not besubjected to any scent delivery. In other words, the user might want toestablish a kind of a “scent exclusion period” for certain scentdelivery unit (or units) that may be associated with a particularlocation. It may also be desirable to schedule such a scent exclusionperiod, which also may be referred to as an anti-event, without havingto alter any of the multiple scheduled events that may happen to addressscent delivery directed to the time and location in question. To thisend, the central controller 102 may be configured to generate commanddata to create such a scent exclusion period in accordance withpre-determined logic without having to alter pre-existing, orsubsequently entered, scenting events.

One difference between an event and an anti-event may be that the eventis configured to schedule a period of activation for a machine while theanti-event is configured to schedule a period of non-activation. In thisway, a user may be able to use anti-events to quickly and easilyschedule ahead a scent exclusion period during which certain machine ormachines should not activate, regardless of other scheduled events thatmay indicate otherwise. Check boxes 420, 440 (FIG. 4) may be used forthis purpose. Additionally, if scent exclusion is no longer desired, auser may be able to revert back to control via the regular scentingevents by simply removing the anti-event.

In another implementation, each scent delivery unit may be associatedwith a fail safe time that indicates a maximum amount of time that amachine will remain on in the event of, for example, a communicationfailure that prevents the unit that has turned on from receiving a turnoff signal. As a result, overscenting by any particular machine due to alost signal within the network may be prevented. In some cases, the failsafe time for each machine may be determined by the user through, forexample, the fail safe entry boxes 320 (FIG. 3). Alternatively, oradditionally, the fail safe time for each machine may be determinedautomatically by the central controller 102 according to a pre-definedalgorithm (e.g., fail safe time is proportional to the size of the roomin which the corresponding scent delivery unit is located).

As noted above, the central controller 102 is configured to generate andsend command data to control each scent delivery unit. In some cases,the fail safe time for each machine, defined manually and/orautomatically as described above, may be sent to the machine every timethat a turn on command is sent. For example, a command to turn on aparticular machine may be sent along with fail safe time data of 10minutes. In turn, the receiving machine may be configured to respond tothe fail safe time of 10 minutes by subsequently turning itself off 10minutes after turning on if no turn off command is received by thattime. That is, if the central controller 102 sends a turn off signal 1minute after having sent the turn on signal (e.g., as part of anactivation period that includes multiple cycles of on/off commands) butthe turn off signal becomes lost or is otherwise never received by themachine, the machine will nevertheless turn off automatically accordingto the fail safe time at the 10 minute mark if no other turn off signalsare received by then from the central controller 102. If the first turnoff signal is never received by the machine, but a subsequent turn onsignal with its own fail safe data is received before the end of theprevious fail safe time period, then the machine may be configured toturn off automatically according to the new fail safe time. If thesubsequently received turn on signal does not include a new fail safetime, the machine may revert back to and newly apply the previouslyreceived fail safe time. Because the fail safe time data is sent alongwith the command data, the fail safe time may be updated as needed basedon user preference and/or machine-specific factors. In some cases, thefail safe time may be sent periodically to the machine along with justsome of the command data sent to said machine. In some cases, thecentral controller 102 may be configured to send only turn on signals toeach scent delivery unit without sending any turn off signals. In such acase, the fail safe time may be sent along with each turn on signal sothat each unit will turn off by itself after a desired amount of timewithout having to receive an explicit turn off signal from the centralcontroller 102. In such a case, a turn off signal sent by the centralcontroller 102 may serve as a redundant process for ensuring that thescent delivery units will not overscent. In some cases, the fail safetime period may be shorter than the desired on period. In such a case,the central controller 102 may adjust and/or prompt the user to adjustthe fail safe time to be at least longer than the desired on period.

In another implementation, the central controller 102 may be configuredto introduce asynchronicity to the start times of multiple scentdelivery units that are scheduled to activate at the same time. As aresult, multiple command data that may otherwise have been transmittedsimultaneously to multiple machines may instead be spread out in time.Such artificially introduced asynchronicity may help prevent overloadingthe network and/or reduce power surges that may occur from multiplemachines being commanded to turn on simultaneously.

In one implementation, the central controller 102 may achieve thedesired asynchronicity by adding a different skew parameter to the starttime of each unit originally scheduled for a synchronous start. Forexample, given a predefined global skew parameter G (e.g., 0.1 seconds),the central controller 102 may add a different multiple of the globalskew parameter (e.g., 0×G, 1×G, 2×G, 3×G, etc.) to each of multiplemachines that have been scheduled by the user to start scenting at thesame time (e.g., 4:00 pm). This way, each of the machines scheduled bythe user to activate at 4:00 pm will start at a slightly different time.

In another implementation, the central controller 102 may be configuredto compensate for unintended asynchronicity in multiple machines thatare configured to behave synchronously, especially under a dutycycle-based control scheme. As noted above, precise control of scentlevels may be achieved by turning each scent delivery unit on and offsuccessively in accordance with a specified duty cycle during saidunit's time of activation. Under this control scheme, a cycle time ofeach scenting unit may refer to the period of time during which oneon-off cycle occurs for a given machine while the duty cycle would referto the percentage of time during each cycle time during said machine isreleasing scent. By synchronizing the start of on-off cycles acrossmultiple machines, the perception of scent variation within a scentingenvironment may be maximized. In other words, if there are multiplemachines that are configured/programmed to be synchronized, the centralcontroller 102 may adjust the generation and/or transmission of commanddata to ensure that all on-off cycles for the three machines occur atthe same time. For example, if three machines A, B, and C are scheduledto activate at 4:00 pm based on a cycle time of 10 minutes and a dutycycle of, respectively, 50%, 40%, and 30%, then the central controller102 may generate command data, as discussed above, to turn on machinesA, B, and C at 4:00 pm and to subsequently turn off the machines at 4:05pm, 4:04 pm, and 4:03 pm, respectively. During the next on-off cycle,the central controller 102 may generate command data to turn on machinesA, B, and C at 4:10 pm and to subsequently turn off the machines at 4:15pm, 4:14 pm, and 4:13 pm, respectively. This cycling process willtypically continue until the scheduled deactivation time, with all threemachines starting each cycle at the same time. In some cases, however, asynchronously scheduled machine may drift from the synchronizedschedule. For example, machine B in the above scenario may start at adelayed start time of 4:01 pm due to a communication error, and this 1minute delay may be propagated to each subsequent on times (e.g., 4:11pm, 4:21 pm, etc.). Upon identifying the delay in machine B, under thesynchronous start implementation, the central controller 102 may alsodelay by 1 minute the start of each cycle for machines A and C. Thisway, machines A, B, and C will continue to turn on at the same time toachieve the desired scenting effect, regardless of any individualmachine delays that may have otherwise broken up the scheduledsynchronicity. In one implementation, the central controller 102 may beconfigured to identify delays in the machines by accessing thecorresponding verification information in the in table 1012.

Accordingly, other implementations are within the scope of the followingclaims.

What is claimed is:
 1. A scent delivery system comprising: a pluralityof scent delivery units, wherein each scent delivery unit is configuredto deliver scent at a variable scent level by being turned on and offsuccessively according to a variable duty cycle, wherein the variableduty cycle includes an “on” time duration and an “off” time duration,wherein each of the plurality of scent delivery units is associated witha corresponding base scent setting, wherein each scent delivery unit ofthe plurality of scent delivery units is configured with a failsafe timeindicating a maximum amount of time that the scent delivery unit willremain “on” after a network communication failure occurs, and whereinthe network communication failure prevents one or more scent deliveryunits of the plurality of scent delivery units from receiving an “off”signal; and a central controller configured to control the plurality ofscent delivery units, wherein controlling the plurality of scentdelivery units includes: defining a group of scent delivery units fromthe plurality of scent delivery units, wherein each scent delivery unitin the defined group corresponds to a base scent setting; receivinginput corresponding to a scent level bias to be applied to the basescent setting of each scent delivery unit included in the group, whereinthe scent level bias is associated with a particular event that isscheduled to occur during a defined time period, wherein the scent levelbias is positive or negative; determining a failsafe time for each scentdelivery unit of the plurality of scent delivery units, whereindetermining the failsafe time for each scent delivery unit includescalculating an amount of time that is proportional to a size of a roomin which the scent delivery unit is located, and wherein the failsafetime determined for the scent delivery unit is longer than the “on” timeduration associated with the scent delivery unit; generating commanddata for each scent delivery unit included in the group, wherein thecommand data is generated based upon the scent level bias, wherein whenthe command data is received at a scent delivery unit included in thegroup, the corresponding scent level of the scent delivery unit isvaried during the time period of the particular event, wherein when thescent level bias is positive, the corresponding scent level of the scentdelivery unit is increased during the particular event, wherein when thescent level bias is negative, the corresponding scent level of the scentdelivery unit is decreased during the particular event, and wherein thecorresponding scent level of the scent delivery unit is increased ordecreased without changing the base scent setting of the scent deliveryunit; and transmitting a data signal individually to each scent deliveryunit of the plurality of scent delivery units, wherein the data signalincludes each of the command data for a recipient scent delivery unit ofthe plurality of scent delivery units and the failsafe time thatcorresponds to the recipient scent delivery unit, wherein receiving thedata signal at the recipient scent delivery unit causes the recipientscent delivery unit to determine whether the received data signalincludes the failsafe time, wherein, when the data signal includes thefailsafe time, the recipient scent delivery unit is configured to updatea prior failsafe time with the received failsafe time, and wherein, whensubsequently the data signal does not include the failsafe time, therecipient scent delivery unit reverts back to and newly applies theprior failsafe time.
 2. The scent delivery system of claim 1, whereinthe central controller is configured to vary the duty cycles that areassociated with each scent delivery unit in the defined group of scentdelivery units based on the scent level bias, the duty cycles beingvaried according to an arithmetic function.
 3. The scent delivery systemof claim 1, wherein the central controller is configured to vary theduty cycles that are associated with each scent delivery unit in thedefined group of scent delivery units based on the scent level bias, theduty cycles being varied according to a geometric function.
 4. The scentdelivery system of claim 1, wherein the central controller is configuredto vary the duty cycles that are associated with each scent deliveryunit in the defined group of scent delivery units based on the scentlevel bias and scent types that are associated with each scent deliveryunit included in the group of scent delivery units.
 5. The scentdelivery system of claim 1, wherein the central controller is configuredto vary cycle times that are associated with each scent delivery unit inthe defined group of scent delivery units based on the scent level bias.6. The scent delivery system of claim 1, wherein the scent deliveryunits are configured to turn on and off successively according to avariable duty cycle that ranges between 5% and 95%.
 7. The scentdelivery system of claim 1, wherein the central controller is configuredto vary the base scent setting that is associated with each scentdelivery unit in the defined group of scent delivery units based on ascent type that is associated with the scent delivery unit.
 8. The scentdelivery system of claim 1, wherein the scent delivery units areconfigured to deliver scent at a variable scent level by, in addition tobeing turned on and off successively according to the variable dutycycle, varying one or more of fan speed, nozzle pressure, and compressorpower of each scent delivery unit, and wherein, based upon a variationin the scent level bias, the central controller sends command data thattakes into account a corresponding variation to a corresponding one ormore of fan speed, nozzle pressure, and compressor power of the scentdelivery units.
 9. The scent delivery system of claim 1, wherein thecentral controller generates and sends a signal to multiple scentdelivery units, the signal reflecting a duty cycle that reflects powercharacteristics to be applied in successively turning the scent deliveryunits on and off.
 10. The scent delivery system of claim 1, wherein thecentral controller generates and sends a signal to multiple scentdelivery units, the signal being a pulse that corresponds to themultiple scent delivery units being turned on or off.
 11. The scentdelivery system of claim 1, wherein the central controller generates andsends a different signal to each of at least two scent delivery units,each different signal reflecting a duty cycle that reflects powercharacteristics to be applied in successively turning a correspondingscent delivery unit on and off.
 12. The scent delivery system of claim1, wherein the central controller generates and sends signals to each ofat least two scent delivery units, wherein the signals sent to a firstof the at least two scent delivery units vary in time relative to thesignals sent to a second of the at least two scent delivery units, andwherein the signals include pulses that correspond to the correspondingscent delivery unit being turned on or off.
 13. A method for deliveringscent comprising: providing a plurality of scent delivery units, whereineach scent delivery unit is configured to deliver scent at a variablescent level by turning scent delivery units on and off successivelyaccording to a variable duty cycle, wherein the variable duty cycleincludes an “on” time duration and an “off” time duration, wherein eachof the plurality of scent delivery units is associated with acorresponding base scent setting, wherein each scent delivery unit ofthe plurality of scent delivery units is configured with a failsafe timeindicating a maximum amount of time that the scent delivery unit willremain “on” after a network communication failure occurs, and whereinthe network communication failure prevents one or more scent deliveryunits of the plurality of scent delivery units from receiving an “off”signal; and controlling the plurality of scent delivery units, whereincontrolling the plurality of scent delivery units includes: defining agroup of scent delivery units from the plurality of scent deliveryunits, wherein each scent delivery unit in the defined group correspondsto a base scent setting; receiving input corresponding to a scent levelbias to be applied to the base scent setting of each scent delivery unitincluded in the group, wherein the scent level bias is associated with aparticular event that is scheduled to occur during a defined timeperiod, wherein the scent level bias is positive or negative;determining a failsafe time for each scent delivery unit of theplurality of scent delivery units, wherein determining the failsafe timefor each scent delivery unit includes calculating an amount of time thatis proportional to a size of a room in which the scent delivery unit islocated, and wherein the failsafe time determined for the scent deliveryunit is longer than the “on” time duration associated with the scentdelivery unit; generating command data for each scent delivery unitincluded in the group, wherein the command data is generated based uponthe scent level bias, wherein when the command data is received at ascent delivery unit included in the group, the corresponding scent levelof the scent delivery unit is varied during the time period of theparticular event, wherein when the scent level bias is positive, thecorresponding scent level of the scent delivery unit is increased duringthe particular event, wherein when the scent level bias is negative, thecorresponding scent level of the scent delivery unit is decreased duringthe particular event, wherein the corresponding scent level of the scentdelivery unit is increased or decreased without changing the base scentsetting of the scent delivery unit; and transmitting a data signalindividually to each scent delivery unit of the plurality of scentdelivery units, wherein the data signal includes each of the commanddata for a recipient scent delivery unit of the plurality of scentdelivery units and the failsafe time that corresponds to the recipientscent delivery unit, wherein receiving the data signal at the recipientscent delivery unit causes the recipient scent delivery unit todetermine whether the received data signal includes the failsafe time,wherein, when the data signal includes the failsafe time, the recipientscent delivery unit is configured to update a prior failsafe time withthe received failsafe time, and wherein, when subsequently the datasignal does not include the failsafe time, the recipient scent deliveryunit reverts back to and newly applies the prior failsafe time.
 14. Themethod of claim 13, further comprising varying the duty cycles that areassociated with each scent delivery unit included in the group of scentdelivery units based on the scent level bias, the duty cycles beingvaried according to an arithmetic function.
 15. The method of claim 13,further comprising varying the duty cycles that are associated with eachscent delivery unit included in the group of scent delivery units basedon the scent level bias, the duty cycles being varied according to ageometric function.
 16. The method of claim 13, further comprisingvarying the duty cycles that are associated with each scent deliveryunit included in the group of scent delivery units based on the scentlevel bias and scent types that are associated with each scent deliveryunit included in the group of scent delivery units.
 17. The method ofclaim 13, further comprising varying cycle times that are associatedwith each scent delivery unit included in the group of scent deliveryunits based on the scent level bias.
 18. The method of claim 13, furthercomprising turning the scent delivery units on and off successivelyaccording to a variable duty cycle that ranges between 5% and 95%. 19.The method of claim 13, further comprising varying the base scentsetting that is associated with each scent delivery unit included in thegroup of scent delivery units based on a scent type that is associatedwith the scent delivery unit.
 20. The method of claim 13, furthercomprising delivering scent at a variable scent level by, in addition tobeing turned on and off successively according to the variable dutycycle, varying one or more of fan speed, nozzle pressure, and compressorpower of each scent delivery unit, and wherein, based upon a variationin the scent level bias, a central controller sends command data thattakes into account a corresponding variation to a corresponding one ormore of fan speed, nozzle pressure, and compressor power of the scentdelivery units.
 21. A non-transitory computer-readable storage mediumstoring software comprising instructions executable by one or morecomputers, which, upon such execution, cause the one or more computersto perform operations comprising: providing a plurality of scentdelivery units, wherein each scent delivery unit is configured todeliver scent at a variable scent level by turning scent delivery unitson and off successively according to a variable duty cycle, wherein thevariable duty cycle includes an “on” time duration and an “off” timeduration, wherein each of the plurality of scent delivery units isassociated with a corresponding base scent setting, wherein each scentdelivery unit of the plurality of scent delivery units is configuredwith a failsafe time indicating a maximum amount of time that the scentdelivery unit will remain “on” after a network communication failureoccurs, and wherein the network communication failure prevents one ormore scent delivery units of the plurality of scent delivery units fromreceiving an “off” signal; and controlling the plurality of scentdelivery units, wherein controlling the plurality of scent deliveryunits includes: defining a group of scent delivery units from theplurality of scent delivery units, wherein each scent delivery unit inthe defined group corresponds to a base scent setting; receiving inputcorresponding to a scent level bias to be applied to the base scentsetting of each scent delivery unit included in the group, wherein thescent level bias is associated with a particular event that is scheduledto occur during a defined time period, wherein the scent level bias ispositive or negative; determining a failsafe time for each scentdelivery unit of the plurality of scent delivery units, whereindetermining the failsafe time for each scent delivery unit includescalculating an amount of time that is proportional to a size of a roomin which the scent delivery unit is located, and wherein the failsafetime determined for the scent delivery unit is longer than the “on” timeduration associated with the scent delivery unit; generating commanddata for each scent delivery unit included in the group, wherein thecommand data is generated based upon the scent level bias, wherein whenthe command data is received at a scent delivery unit included in thegroup, the corresponding scent level of the scent delivery unit isvaried during the time period of the particular event, wherein when thescent level bias is positive, the corresponding scent level of the scentdelivery unit is increased during the particular event, wherein when thescent level bias is negative, the corresponding scent level of the scentdelivery unit is decreased during the particular event, wherein thecorresponding scent level of the scent delivery unit is increased ordecreased without changing the base scent setting of the scent deliveryunit; and transmitting a data signal individually to each scent deliveryunit of the plurality of scent delivery units, wherein the data signalincludes each of the command data for a recipient scent delivery unit ofthe plurality of scent delivery units and the failsafe time thatcorresponds to the recipient scent delivery unit, wherein receiving thedata signal at the recipient scent delivery unit causes the recipientscent delivery unit to determine whether the received data signalincludes the failsafe time, wherein, when the data signal includes thefailsafe time, the recipient scent delivery unit is configured to updatea prior failsafe time with the received failsafe time, and wherein, whensubsequently the data signal does not include the failsafe time, therecipient scent delivery unit reverts back to and newly applies theprior failsafe time.
 22. The medium of claim 21, wherein the operationsfurther comprise varying the duty cycles that are associated with eachscent delivery unit included in the group of scent delivery units basedon the scent level bias, the duty cycles being varied according to anarithmetic function.
 23. The medium of claim 21, wherein the operationsfurther comprise varying the duty cycles that are associated with eachscent delivery unit included in the group of scent delivery units basedon the scent level bias, the duty cycles being varied according to ageometric function.
 24. The medium of claim 21, wherein the operationsfurther comprise varying the duty cycles that are associated with eachscent delivery unit included in the group of scent delivery units basedon the scent level bias and scent types that are associated with eachscent delivery unit included in the group of scent delivery units. 25.The medium of claim 21, wherein the operations further comprise varyingcycle times that are associated with each scent delivery unit includedin the group of scent delivery units based on the scent level bias. 26.The medium of claim 21, wherein the operations further comprise turningthe scent delivery units on and off successively according to a variableduty cycle that ranges between 5% and 95%.
 27. The medium of claim 21,wherein the operations further comprise varying the base scent settingthat is associated with each scent delivery unit included in the groupof scent delivery units based on a scent type that is associated withthe scent delivery unit.
 28. The medium of claim 21, wherein theoperations further comprise delivering scent at a variable scent levelby, in addition to being turned on and off successively according to thevariable duty cycle, varying one or more of fan speed, nozzle pressure,and compressor power of each scent delivery unit, and wherein, basedupon a variation in the scent level bias, a central controller sendscommand data that takes into account a corresponding variation to acorresponding one or more of fan speed, nozzle pressure, and compressorpower of the scent delivery units.